Commutator.



'E'. W. REEVES. GOMMUTHVATOR. APPLIUATIONTILEQ DB0 994,480, 'Patened June 6,1911.

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. EEEDERICK'W. REEVES, 'or rrr'rsiaune, iEii'NsYLvaNIA.

Y Application led December 4, 1909. t Serial No. 531,289, .f

To all wlmm 'it may concern:

Be it known that I, FREDERICK REEVES,4 citizen -.of the United States, residing at.

Pittsburg, N.'S., in the county of Allegheny and State of Pennsylvania, have invented certain new and useful yImprovements in Commutators; and I do declare the'following to be a full, clear, and exact descriptionA of the invention, such as will enable'othersl skilled in the art to which it appertainsto make and use the same, reference being had to the accompanying drawings, and tothe letters and figures of reference marked thereon, which form a part of this specification. j

My invention relates to improvements in commutators for electric generators and mol tors, and has for 'its' objects the improve-` ment thereof to eliminate or .reduce the heating occasioned therein to a minimum,

whether it be due to friction between the same and attending brushesfto sparking, or

to other causes',- by forming thevoperating -periphery of the commutator in such' manner as to .cause the same to shift its Contact with the brushes, as well as to cause a circulation of air tliere'about during rotation.

IVith the above object in vi'eW, the invention consists of certain improvements, combination and arrangement of parts as will be hereinafter more fully described and pointed out in the appended claims.

In the accompanying drawings which form apart of this specification, I have illustrated my improved commutator in various ways,

vFigure I, is' a rear elevation of the same. Fig. II, a side elevation. Fig. III, a longitudinal section, on the line 0,-0 of Fig. I, Fig. IV, is a transverse section, on the line X'-X'of Fig. II. Fig. V, is'a longitudinal side elevation of a modilied form of the commutator. Fig. VI, is a similar view of another 'modified form, said device having;r like detail parts, in all views, except Figs. V and VI, designated by numerals of like character. y

The structure disclosed in said drawings, comprises a. pair ot' clamping' h ads l and Q between which the eommntator segments or bars are secured, the former head having integral therewith a sleeve to engage over the armature shaft where it is snit-ably scenred in operative position, the latter head being removably fitted upon the free end of .theirexterior or working surface with a plurality of alternate grooves and ribs l0 and 1l the'sleeve, said heads being secured to one l u 1 v l A v 'I l i i Specieati'o'n'of Letters Patent. Patented "June 6, 1911.

another by means of bolts 4 passing,therel through and provided with nuts 5, each head having formed upon its inner face portion an lannular commutator segment retaining flange 6, vsaid flange being of Wedge shape in cross-section with the taper wholly, but not necessarily, uponY the inner, portion thereof.

ff The eommutator segments, or bars, 7, are here shown as being but 'four in number,'sep arated from one another by a strip of insu.

"latingmaterial 8 extending' thereacross, which segments are provided at' each side with a groove corresponding in cross-section with that of the annular flanges of the heads,

being insulated from the heads by the interf posed insulatingrin'gs 9. These commutator segments or bars, are each 'provided -upon respectively, the raised portions or ribs conlstituting the working surfaces and are each Vof a -width corresponding to the Width of the grooves.y In positioning these segments or bars, every alternate one is reversed, sol as to cause the ribs of one-to aline with the 'Y grooves of the adjacent one, as shown.

By constructing a commutator 'in the above manner, it will be readily apparent that when the brushes (not shown) are brought in Contact with the ribbed working surface thereof that the points of contact will be alternately shifted in the passing of each succeeding segment under the brushes.' This constant shifting of frictional contact, in a backl and forth manner, together with the induced current of airoccasioned Y by itsalternate alined groove and ribbed segmental structure, allows the adjacent portions to alternately be subjected to friction i andA a blast of cool air, thus avoiding heating as well as reducing the tendency to spark during operation.

As the improvements are applicable tov col-Y lector rings as 'well as commutators, I have,

' at Fig. V, shown a pair of such rings mounted upon a suitable holder 12, the various segments 13 which are assembled to form the respective rings each having the spaces ilu-rebetween filled with a strip of meta-l 14 so that ythe segments of each ring will Abe as a unit. f

At Fig'. VI, I have shown a side elevation of a modified form of commutator, in which the grooves and ribs 2O and 21, respectively, are spil-ally inclined, so us to effect-:i more gradual change of Contact with the brushes instead of an abrupt one as in the former case.

Having thus shown and described my invention, what I claim and desire to secure by.

Letters Patent is:

1. In :L commutator, :L plurality of insulated segments each having a plurality of transversely disposed alternate ribs and grooves in its face.

2. In u eonnnutator, a plurulitv of insulated segments eneh having` a plurality of rnnsversely disposed alternate grooves und ribs in its face, the grooves oi" one segment alining with the ribs of tlie urljmfent one.

3. In u eonunutzrtor, n plurality of insulated segments euch having u. plurality of transversely disposed alternate `grooves :unl ribs in its fume, the grooves of one segment alining with the ribs of the adjacent one, seid grooves und ribs being of the saune dimensions in cross-section.

In testimony whereof, I allix my signature. in presence oi. tivo witnesses.

FREDERICK IV. ,fRllVllJh lVitnesses:

C. B. MILLIGAN, R. S. HARRISON. 

